Cell tower monitoring systems and methods

ABSTRACT

Faults along a transmission pathway of a cell tower disrupt or prevent the cell tower from connecting user equipment (UE) to a cellular network. A cell tower monitoring and diagnostic system identify faults that occur along the transmission pathway and provide information regarding the faults to a network management center. The cell tower monitoring and diagnostic system can include multiple monitoring devices that are electrically coupled to portions of the transmission pathway. Each of the monitoring devices outputs an inquiry signal along the portion of the transmission pathway and receives a response signal in return. Each of the monitoring devices generates and transmits an output based on the response signal. A base station analyzes or evaluates the outputs from the monitoring devices to identify a fault on the transmission pathway. The base station can also determine the location and type of the fault based on the output.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/845,467, filed Apr. 10, 2020, entitled, “CELL TOWER MONITORINGSYSTEMS AND METHODS,” which is incorporated herein by reference in itsentirety for all purposes.

BACKGROUND

Cell phones, mobile devices, and other user equipment (UE) connect tocell towers to access one or more services of a cellular network, suchas voice call services, text messaging services, data services and otherservices. The UE and cell tower use radio transmissions to exchangecommunications. At the cell tower, these radio communications arereceived and transmitted along a transmission pathway of the cell towerto the cellular network. The transmission pathway includes variouscables, connectors and equipment that carry the communications to andfrom UEs through the cell tower. Degradation or faults along thistransmission pathway can prevent the cell tower from operatingefficiently or even prevent it from communicating with the UE at all.Such failure or degradation can adversely affect the functioning of thecell tower and impact UEs that are served by the cell tower.

To repair the cell tower and restore it to normal operation, atechnician can be dispatched to diagnose and repair the failure ordegradation. While some failures are obvious or easy to diagnose andcorrect, other failures may not be so obvious. For the failures that arenot obvious to diagnose, the technician may have to go through a processof replacing various parts and equipment of the cell tower in an attemptto figure which part or piece of equipment actually failed or wascausing the degradation. Not only does such a process take time, it isalso expensive since parts and equipment may be replaced when notneeded. Additionally, if the technician does not have the appropriateequipment needed to repair the failure or degradation of the cell tower,the technician may have to return to a service location to obtain thenecessary equipment, further delaying repairs.

There exists a need for monitoring and diagnostic systems and methodsthat can monitor the status of the of a cell tower, identify faults orfailures in the cell tower and provide fault information to networkmanagement so that the cell tower can be repaired.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an example cell tower monitoring anddiagnostic system.

FIG. 2 is a further example of a cell tower monitoring and diagnosticsystem.

FIGS. 3A-3B are portions of an example cable of a transmission pathway.

FIG. 4 is an example cell tower monitoring and diagnostic process.

FIG. 5 is another example cell tower monitoring and diagnostic process.

DETAILED DESCRIPTION

Cell towers are an important link in the cellular network. The celltower uses radio communications to allow user equipment (UE) to accessthe cellular network. Various components and equipment of the cell towerprovide the communications capability of the tower. However, failures,degradation and other faults of the components and equipment canadversely affect the operation of the cell tower. The cell towermonitoring and diagnostic systems and methods described herein monitorthe components and equipment of the cell tower for faults and identifythe location and type of the faults. This information is provided to amanagement location, system or person of the cellular network so thatthe faults can be repaired. By identifying a presence of a fault and thelocation and type of the fault, the repair process to correct the faultis more efficient. A technician can be dispatched to specifically repairthe identified fault and can be prepared to repair the fault since theyknow the location and type of the fault. This allows the technician togather the necessary equipment, travel to the cell tower and repair orreplace the faulty component or equipment. Additionally, some faults canbe mitigated by network management by adjusting an operating parameterof the cell site. In this case, a technician does not need to bedispatched and the fault can be mitigated by the network management.

FIG. 1 illustrates an example cell tower monitoring and diagnosticsystem 100 that includes a cell tower 110, a monitoring device 210, anda base station 250. A UE connects to the cell tower 110 and exchangesradio communications with the cell tower 110. By exchangingcommunications with the cell tower 110, the UE can access variousfeatures of the cellular network of which the cell tower 110 is a part.Radio communications received by the cell tower 110 from the UE arepassed along a transmission pathway 112 to the cellular network by acellular network connection 126. Similarly, radio communication sentfrom the cellular network to the UE are passed from the cellular networkconnection 126 along the transmission pathway 112 and broadcasted fromthe cell tower 110. Faults 124 on the transmission pathway 112 canprevent or hinder the exchange of radio communications between the UEand the cellular network by blocking or degrading a radio communicationalong the transmission pathway.

The transmission pathway 112 includes various components and equipmentthat are used to send and receive radio communications with the UE andthe cellular network. For example, the radio transmission pathway 112can include one or more antenna 114, cables 116, connectors 118, andother equipment 120, such as a switch 122. The various equipment andcomponents of the transmission pathway 112 are interconnected to providethe communication between the cellular network and the UE. The antenna114 of the transmission pathway 112 is used to receive and transmitradio communications with the UE. Cables 116 electrically connect theequipment and components of the transmission pathway 112. Connectors 118can couple cables 116 together and couple cables 118 to various otherequipment and components. The equipment 120 of the transmission pathway112 can assist with transmitting signals along the transmission pathway112. Example equipment 120 can include the switch 122 that is used todirect signals along the transmission pathway 112, analog-to-digitalconversion equipment, transceivers, and other equipment that assists thecell tower 110 with transmitting signals along the transmission pathway112.

Any of the various components and equipment of the transmission pathway112 can fail or degrade, creating a fault 124. Example faults 124 caninclude breaks in the cables 116, water or foreign materials in thecables 116 or connectors 118, a failure of the antenna 114, or a failureof a piece of equipment 120. Due to a fault 124, signals along thetransmission pathway 112 can be blocked or degraded. Blocking of signalsalong the transmission pathway 112 can disable the cell tower 110,preventing its use in the cellular network. Degradation of signals alongthe transmission pathway 112 may not disable the cell tower 110 but canreduce its operating efficiency, such as reducing Key PerformanceIndicators (KPIs) of the cell tower, or creating Quality of Service(QoS) issues. The KPIs are various metrics that are tracked to assesshow efficiently or correctly the cell tower 110 is operating. The QoSare indications of how satisfied the users of the cellular network arewith the cellular service. The reduction in a KPI or the creation of aQoS issue can adversely affect the operating efficiency of the celltower 110 and the cellular network of which the cell tower 110 is apart. As such, faults 124 can have a significant impact on the cellularnetwork and its users.

The cellular network connection 126 can be a fiber optic or othercommunication connection that links the transmission pathway 112 of thecell tower 110 to the rest of the cellular network. Communicationsbetween the UE and the cellular network are carried by the transmissionpathway 112 to the cellular network through the cellular networkconnection 126.

Multiple monitoring devices, like monitoring device 210 and the basestation 250 work together to monitor the transmission pathway 112 forfaults 124. Each of the monitoring devices are electrically coupled to aportion of the transmission pathway 112 to collect data regarding thetransmission pathway 112. The collected data is transmitted from themonitoring devices to the base station 250 where it is analyzed orevaluated to identify if a fault 124 is present in the transmissionpathway 112. By using multiple monitoring devices located along thetransmission pathway 112, the base station 250 receives data regardingthe whole of the transmission pathway 112. This allows the base station250 to identify a fault 124 anywhere along the transmission pathway 112in a quick and efficient manner. Additionally, the base station 250 cananalyze and evaluate the data from the monitoring devices to determine alocation 254 and type 256 of a fault 124. By quickly and efficientlyidentifying the location 254 and type 256 of a fault 124, the cell towermonitoring and diagnostic system 100 performs the necessary fault 124diagnosis that a technician would otherwise have to perform. This allowsthe technician to more efficiently repair or correct a fault 124, asthey do not need to go through the process of removing and replacingportions of the transmission pathway 112 while attempting to repair afault 124.

The monitoring device 210 is an example of one of the multiplemonitoring devices that are located along the transmission pathway 112.The monitoring device 210 includes an identification 212, a signalmodule 214, an output 234, a communication module 236, and a powersource 238. The monitoring device 210 is a small device that can beplaced at locations along the transmission pathway 112 or can beintegrated into portions of the transmission pathway 112. As mentioned,the monitoring device 210 is electrically coupled to a portion of thetransmission pathway 112, such as at the antenna 114, cable 116,connector 118 or other equipment 120 of the transmission pathway 112. Togather data regarding the portion of the transmission pathway 112 towhich the monitoring device 210 is coupled, the signal module 214 of themonitoring device 210 transmits an inquiry signal 216 along the portionof the transmission pathway 112 and receives a corresponding responsesignal 224 back from the portion of the transmission pathway 112.Features, characteristics and other information regarding the responsesignal 224 are output 234 by the monitoring device 210 and transmittedto the base station 250 by the communication module 238.

The identification 212 of the monitoring device 210 can be a series ofnumeric, alphanumeric or other characters that are unique the monitoringdevice 210. The identification 212 can assist with locating along whichportion of the transmission pathway 112 the monitoring device 210 iscoupled. The identification 212 of the monitoring device 210 can bepermanent or it can be modifiable, such as programmable. The monitoringdevice 210 provides its identification 212 with the output 234 to thebase station 250 to allow the base station 250 to identify theparticular monitoring device 210 that provided the output 234. Todetermine a location of the monitoring device 210 along the transmissionpathway 112, the base station 250 can maintain a record or database thatcorrelates the identification 212 of the monitoring device 210 with alocation along the transmission pathway 112. Alternatively, theidentification 212 can include an indication of the location of themonitoring device 210 along the transmission pathway 112. For example,the transmission pathway 112 can be divided into a grid or portions anda structure or value of the identification 212 can include informationregarding the grid or portion of the transmission pathway 112 at whichthe monitoring device 210 is located. Being able to determine a locationof the monitoring device 210, such as by the identification 212 assiststhe base station 250 in identifying the location 254 of a fault 124.

The signal module 214 of the monitoring device 210 outputs the inquirysignal 216. The inquiry signal 216 has characteristics 218, such as aninquiry frequency 220, an inquiry energy 222, other characteristics orcombinations thereof. The inquiry signal 216 is output as a pulse alongthe portion of the transmission pathway 112 to which the monitoringdevice 210 is coupled. The inquiry frequency 220 is the frequency of theinquiry signal 216, such as the frequency at which the inquiry signal216 is output. In an example, the inquiry signal can be output at a lowinquiry frequency 220, such as a frequency of 100 Hz to 500 Hz, which isa range in which there is no direct interference or harmonicinterference with the frequency range used by the cell tower for radiotransmission. Similarly, the inquiry energy 222 is the energy of theinquiry signal 214, such as the energy at which the inquiry signal isoutput. The inquiry frequency 220 and inquiry energy 222 of the inquirysignal 216 can be predetermined values that are known to the basestation 250. For example, the base station 250 can be instructed orprogrammed that the inquiry frequency 220 and inquiry energy 222 arefixed values. Alternatively, the base station 250 can include a databasethat correlates the identification 212 of the monitoring device 210 withthe predetermined values for the inquiry frequency 220 and inquiryenergy 222. In another example, the output 234 can include an indicationof the inquiry frequency 220 and inquiry energy 222, such as providing avalue for each of the inquiry frequency 220 and the inquiry energy 222.

The inquiry signal 216 is output along the portion of the transmissionpathway and reflects back along the portion of the transmission pathway112. The reflection of the inquiry signal 112 can be received by thesignal module 214 as the response signal 224. Alternatively, an inquirysignal from another monitoring device located on a neighboring portionof the transmission pathway 112 can be received by the signal module 214as the response signal 224.

As the inquiry signal 216 transmits along the portion of thetransmission pathway 112, the inquiry frequency 220 and inquiry energy222 can be altered by various properties of the portion of thetransmission pathway 112, such as by one or more material properties ofthe portion of the transmission pathway 112 or a fault 124 on theportion of the transmission pathway 112. The response signal 224 has aperformance feature 226 that is indicative of the change caused by thetransmission of the inquiry signal 216 along the portion of thetransmission pathway. The performance feature can include a responsefrequency 228, a response energy 230, or a return time 232. The responsefrequency 228 can be the frequency of the response signal 224 receivedby the signal module 214 of the monitoring device 210. Alternatively,the response frequency 228 can be an amount of change between theinquiry frequency 220 and the frequency of the response signal 224. Theamount of change between the inquiry frequency 220 and the frequency ofthe response signal 224 can be calculated or determined by signal module214 and included in the output 234. Similarly, the response energy 230can be a measure of the energy of the response signal 224 or an amountof change between the inquiry energy 222 and the energy of the responsesignal 224. The return time 232 is optional as is the elapsed timebetween outputting the inquiry signal 216 and receiving the responsesignal 224. The return time 232 can be calculated or timed by the signalmodule 214. In some cases, a fault 124 on the portion of thetransmission pathway 112 can prevent the response signal 224 from beingreceived by the signal module 214. For example, a fault 124 may preventthe reflection of the inquiry signal 216. If no response signal 224 isreceived after outputting the inquiry signal 216, the performancefeature 224 of the response signal 224 can be the lack of one or more ofresponse frequency 228, the response energy 230, or the return time 232.

The output 234 can include the performance feature 226 of the responsesignal 224, such as one or more of the response frequency 228, theresponse energy 230 or return time 232. As previously mentioned, theoutput 234 can also include the identification 212 of the monitoringdevice 210 or an indication of the inquiry frequency 220 and inquiryenergy 222. The communication module 236 transmits the output 234 to thebase station 250. In an example, the output 234 can be a 4 bit-8 bitdata transmission that is sent by the communication module 236 to thebases station 250. Communication between the communication module 236and the base station 250 can be through a wired or a wirelessconnection. The wired connection between the communication module 236and the base station 250 can be through a local area network (LAN) orother wired communication protocol or connection. The wirelessconnection between the communication module 236 and the base station 250can be a Wi-Fi, Bluetooth®, near-field communication, or other wirelesscommunication protocol or connection. Additionally, the wirelessconnection can be through a mesh network that includes multiple,wirelessly interconnected monitoring devices similar to the monitoringdevice 210. In the mesh network, the output 234 can be transmitted fromthe monitoring device 210 to another monitoring device, and so on untilthe output 234 reaches the base station 250.

The power source 238 of the monitoring device 210 provides power for thevarious functions and features of the monitoring device 210, such as thesignal module 214 and communication module 236. In an example, the powersource 238 can be a battery or other energy storage device that provideselectrical power to the various functions and features of the monitoringdevice 210. Alternatively, the power source 238 can be an external powerto which the monitoring device 210 is coupled, such as an electricalpower connection.

The base station 250 includes a fault detection module 252 and acommunication module 258. The base station 250 can be positioned withinthe cell tower 110 to communicate with multiple monitoring devices thatare located along the transmission pathway, such as the monitoringdevice 210. The base station 250 can be connected to an external powersource or can include an internal power source, like a battery toprovide electrical power for the various functions and features of thebase station 250. In an embodiment, the base station 250 can beinstalled in the cell tower 110 as a stand-alone or separate device orsystem. Alternatively, the functions and features of the base station250 can be integrated into a portion of the cell tower 110, such as abase bank of the cell tower 250.

The base station 250 receives the output 234 from the monitoring device210 and the fault detection module 252 processes and analyzes the output234. The output 234 is based on and can include the performance feature226 of the response signal 224. The fault detection module 252 cananalyze or evaluate output 234 to identify a fault 124 on the portion ofthe transmission pathway 112 associated with the monitoring device 210.In an embodiment, the fault detection module 252 can detect a fault 124by comparing a value or characteristic of the output 234 to a thresholdor range. If the value or characteristic of the output 234 is over orunder the threshold, depending on the threshold, or outside of therange, then there is an indication that there is a fault 124 on theportion of the transmission pathway 112.

For example, it can be expected that the inquiry characteristics 218 ofthe inquiry signal 216 will decrease as the inquiry signal 216 transmitsand reflects along the portion of the transmission pathway 112. Thedecrease of the inquiry characteristics 218 can be calculated ordetermined for the portion of the transmission pathway. In an example,the decrease of the inquiry characteristics 218 can be an amount ofexpected loss of the inquiry frequency 220 or inquiry energy 222. Theexpected loss can be a predetermined value and included in the faultdetection module 252. The value of expected loss can also include atolerance to account for real-world conditions that may cause the amountof expected loss to be slightly different. If the difference between theinquiry characteristic(s) 218 and the output 234 exceeds the value ofthe expected loss, then a fault 124 is identified on the portion of thetransmission pathway 112. Similarly, the return time 232 of the responsesignal 224 can be an expected amount. The expected return time can bedetermined based on an average or other statistical metric of repeatedlyreceiving the response signal 224 from along the portion of thetransmission pathway 112 or it can be a predetermined or calculatedvalue associated with the portion of the transmission pathway 112. Ifthe return time 232 is not within a range of the expected return time itcan be an indication that there is a fault 124 on the portion of thepathway 112.

In another example, it can be expected that the output 234 will bewithin a predetermined range of values if there is not a fault 124 onthe portion of the transmission pathway 112. To identify a fault 124,the fault detection module 250 can compare the value of the output 234to the predetermined range of values. If the value of the output 234 isnot within the predetermined range of value, then a fault 124 isidentified on the portion of the transmission pathway 112.

The expected threshold or range of the value or characteristic of theoutput 234 can be based on the location of the monitoring device on thetransmission pathway 112. For example, if the monitoring device 210 isplaced on a cable 116 of the transmission pathway 112, the expectedthreshold or range of the value or characteristic of the output 234 canbe a first threshold or range. If the monitoring device 210 is placed ona connector 118 of the transmission pathway 112, the expected thresholdor range of the value or characteristic of the output 234 can be asecond threshold or range. The fault detection module 252 can maintainor access a database that stores the various thresholds or ranges of thevalues or characteristics for the various portions of the transmissionpathway 112. The fault detection module 252 can use the variousthresholds or ranges of the values or characteristics when determiningif a fault is present on the transmission pathway 112. For example, thefault detection module 252 can use the identification 212 of themonitoring device 210 to retrieve the appropriate threshold or range ofthe value or characteristic of the output 234 associated with thelocation of the monitoring device 210 along the transmission pathway112. The fault detection module 252 can then compare the output 234 tothe appropriate threshold or range of the value or characteristic andidentify if a fault 124 is present on the portion of the transmissionpathway 112.

The location 254 of a fault 124 can also be determined by the faultdetection module 252. By knowing the location of the monitoring device210, if the fault detection module 252 identifies that a fault 124 ispresent based on the output 234 from the monitoring device 210, then thefault detection module 252 can determine that the location 254 of afault 124 is on the portion of the transmission pathway 112 at which themonitoring device 210 is located. The fault detection module 252 canalso determine the location 254 of a fault 124 using information frommultiple monitoring devices. By knowing the locations of the monitoringdevices along the transmission pathway 112 and analyzing the output 234from each of the monitoring devices, the fault detection module 252 candetermine the location 254 of the fault 124 on the transmission pathway112. For example, the fault detection module 252 can compare the outputsof a series of monitoring devices along the transmission pathway 112. Ifthe output from one of the monitoring devices deviates from the outputof the rest of the monitoring devices, then the fault detection module252 can determine that the location 254 of the fault 124 is on theportion of the transmission pathway 112 associated with the onemonitoring device. Similarly, the fault detection module 252 can alsocompare the output 234 from neighboring monitoring devices. If there isa deviation in the output 234 from each of the neighboring monitoringdevices, then the fault detection module 252 can determine the location254 of a fault 124 as being on the portion of the transmission pathway112 between the two neighboring monitoring devices.

Additionally, the fault detection module 252 can provide a more detailedlocation 254 of a fault 124 on the transmission pathway 112. Byanalyzing or evaluating the output 234, the fault detection module 252can determine a distance that a fault 124 is located from the monitoringdevice 210. In an embodiment, the output 234 can include the return time232 that can be used to calculate a distance a fault 124 is from themonitoring device 210. For example, the fault detection module 252 candetermine that a fault 124 is 12 ft from the monitoring device 210 basedon the return time 232. The precise location 254 of a fault 124 can beprovided to the network management center or a technician to allow themto more efficiently repair the fault.

The fault detection module 252 can also determine a type 256 of a fault124. Similar to the location 254, the fault detection module 252 cananalyze or evaluate a value or characteristic of the output 234 todetermine the type 256 of a fault 124. The fault detection module 252can have or access a record or database that correlates various thetypes 256 of faults 124 with a threshold or range of values orcharacteristics of the output 234. The types 256 of faults 124 and theassociated output 234 thresholds, ranges or characteristics can befurther correlated to specific portions of the transmission pathway 112or the location of the monitoring device 210. In an example, a firsttype of fault 124 can be associated with a first threshold value of theoutput 234 and a second type of fault 124 can be associated with asecond threshold value of the output 234. The fault detection module 252can compare the output 234 from the monitoring device 210 with the firstand second thresholds to determine which type of fault 124 is indicatedby the output 234. Additionally, the fault detection module 252 candetermine a type 256 of a fault 124 using the outputs 234 from multiplemonitoring devices. For example, the fault detection module 252 can usethe outputs 234 of neighboring monitoring devices to determine the type256 of a fault 124.

The communication module 258 of the base station 250 allows the basestation 250 to communicate 260 with the monitoring device(s) 210 and anexternal system or network 262. As discussed previously, thecommunication module 236 of the monitoring device 210 can communicatewith the communication module 258 of the base station 250 using acommunication protocol or connection, such as a Bluetooth® connection.Communication 260 with the monitoring device 210 can include receivingthe output 234 from the monitoring device 210 and sending instructionsto the monitoring device 210. The base station 250 can transmitinstructions to the monitoring device 210 and cause it to perform one ormore actions, such as output the inquiry signal 216 and provide theresulting output 234 back to the base station 250. In this manner, thebase station 250 can instruct the monitoring device 210 to provide theoutput 234. The base station 250 can provide such instruction on aschedule or when instructed to, such as by the network managementcenter. Additionally, by instructing the output 234 from the monitoringdevice 210, the base station can interrogate various portions of thetransmission pathway 112 for faults 124, as needed.

The communication module 258 of the base station 250 can communicatewith an external system or network 262 to provide information regardingidentified faults 124 on the transmission pathway 112, such as thelocation 254 and type 256 of faults 124. Communication between thecommunication module 258 and the external system or network 262 can bethrough the cellular network connection 126 or another communicationconnection. The external system or network 262 can include a networkmanagement center or other network management system or location. Thebase station 250 can transmit a data message to the network managementcenter using the communication module 258. The data message can includefaults 124 identified on the transmission pathway 112 of the cell tower110. The network management center can use this fault 124 information toschedule repairs or take other actions to correct the faults 124.Additionally, the network management center can communicate with thebase station 250, such as to send instructions. For example, the networkmanagement center can monitor performance parameters of the cell tower110, such as the KPIs. If the network management center notices that theKPIs are decreasing, the network management center can instruct the basestation 250 to cause the monitoring device 210 generate the output 234so that the base station 250 can identify if a fault 124 is present onthe transmission pathway 112. In another example, the network managementcenter can provide the base station 250 a schedule for the base station250 to poll the monitoring devices of the cell tower 110 and determineif a fault 124 is present on the transmission pathway 112.

FIG. 2 illustrates an example cell tower monitoring and diagnosticsystem 200. The cell tower monitoring and diagnostic system 200 includemultiple monitoring devices 210 a-210 d placed along the transmissionpathway 112 of a cell tower. The monitoring devices 210 a-210 dcommunicate with the base station 250. The base station 250 analyzes orevaluates the outputs from the monitoring devices 210 a-210 d toidentify faults on the transmission pathway 112. If a fault isidentified, the base station 250 can send a message to the networkmanagement center 150 so that the fault can be repaired.

In the example of FIG. 2 , a first monitoring device 210 a is integratedwith the switch 122 of the transmission pathway 112, a second monitoringdevice 210 b is placed on a first cable 116 a, a third monitoring device210 c is placed on the connector 118 and a fourth monitoring device 210d is placed on a second cable 116 b. The monitoring devices 210 a-210 doutput an inquiry signal along the portion of the transmission pathway112 they are coupled to and receive a response signal that is eitherreflected back along their portion of the transmission pathway 112 orthat is an inquiry signal from another one of the monitoring devices 210a-210 d. For example, the response signal of the third monitoring device210 c can be a reflection of the inquiry signal the third monitoringdevice 210 c outputs along the connector 118, or the response signal ofthe third monitoring device 210 c can be the inquiry signal transmittedby the second 210 b or fourth monitoring device 210 c.

Each of the monitoring devices 210 a-210 d generates an output based ona performance feature of the response signal each monitoring device 210a-210 d received. The monitoring devices 210 a-210 d then send theoutput to the base station 250. The base station 250 analyzes andevaluates the outputs from the monitoring devices 210 a-210 d toidentify faults on the transmission pathway 112. The base station 250also determines other details regarding the faults, such as the locationand type of the faults. The resultant fault data can be transmitted fromthe base station 250 to the network management center 150.

FIG. 3A illustrates an example cable 116 of the transmission pathway112, and FIG. 3B illustrates the cable 116 with a fault 124. In theexample of FIG. 3A, the cable 116 includes a monitoring device 210electrically coupled to the cable 116. The monitoring device outputs aninquiry signal 216 along the cable 116 and receives a response signal224 a. The response signal 224 a has the expected characteristics sincethe cable 116 of FIG. 3A does not include a fault 124. The responsesignal 224 a can be substantially similar to the inquiry signal 216,with minor losses due to being transmitted along the cable 116.

In the example of FIG. 3B, the monitoring device 210 outputs the inquirysignal 216 along the cable 116. However, the cable 116 of FIG. 3B has afault 124 that prevents the inquiry signal 116 from travelling furtheralong the cable 116 of FIG. 3B. A response signal 224 b reflects fromthe fault 124 and is received by the monitoring device 210. The responsesignal 224 b does not have the expected characteristics since theinquiry signal 116 did not transmit along the cable 116 of FIG. 3B asexpected due to the fault 124. In an example, the fault 124 can causethe response signal 224 b to have greater losses, such as a lower energythan expected. The monitoring device generates an output based on theperformance feature of the response signal 224 b. The output istransmitted by the monitoring device 210 to a base station that willidentify the fault 124 on the cable 116 of FIG. 3B based on the output.

FIG. 4 is an example cell tower monitoring and diagnostic process 400.At 402, an inquiry signal is output along a portion of the transmissionpathway, such as by a monitoring device 210 of FIG. 1 . As previouslydiscussed, the inquiry signal has associated characteristics, like aninquiry frequency and an inquiry energy. At 404, a response signal isreceived in response to the inquiry signal, such as by the monitoringdevice 210. The response signal can be a reflection of the inquirysignal from the portion of the transmission pathway. The response signalhas a performance feature, such as a response frequency, response energyand a return time. At 406, the performance feature of the responsesignal is output and at 408 the output is transmitted, such as by themonitoring device 210 to the base station 250 of FIG. 1 .

At 410, a fault along the portion of the pathway is identified based onthe performance feature of the output of 406. In an embodiment, the basestation 250 can analyze or evaluate the performance feature to identifythe fault. For example, the performance feature can be compared to thecharacteristics of the inquiry signal of 402 to identify if a fault ispresent along the portion of the transmission pathway. If the differencebetween the performance feature and the characteristics of the inquirysignal are outside of a threshold or range, the fault can be identified.At 412, optionally, a location and type of the fault of 410 can bedetermined based on the performance feature. Again, the performancefeature can be analyzed and evaluated to determine the location of thefault on the transmission pathway and the type of fault. The locationand type of the fault can help the technician efficiently andeffectively repair the fault.

At 414, optionally, a message with the identified fault can betransmitted to a network management center, such as 150 of FIG. 2 . Themessage can include that a fault has been identified and the locationand type of the fault from 412. The network management center can usethis message to schedule a repair of the fault or take other action, ifnecessary, to address the fault. Depending on the type of the fault, thenetwork management center may be able to remotely implement a repairusing software, such as altering an operating parameter of the celltower to bypass or mitigate the fault.

At 416, optionally, an instruction to output another inquiry signal canbe generated. The instruction can be generated by the base station 250and provided to the monitoring device 210 to repeat the process 400. Insome embodiments, the transmission pathway can be branched and repeatingthe process 400 can allow each branch of the transmission pathway to bechecked for faults. Repeating the process 400 can also build up anoperating history of the cell tower and the base station 250 can usethis historical information to monitor for degradation of portions ofthe transmission pathway over time. For example, the base station 250can perform trend analysis on the performance feature over time to seeif the performance feature indicates that the portion of thetransmission pathway is degrading. In this manner, the base station maybe able to identify faults before they occur and allow preemptiverepairs to be performed on the portion of the transmission pathway.

FIG. 5 is another example cell tower monitoring and diagnostic process500. At 502, a first inquiry signal is output along a first portion ofthe transmission pathway. The first inquiry signal can be output by abase station, such as 250 of FIG. 1 that is electrically coupled to thefirst portion of the transmission pathway. Alternatively, another devicecan be electrically coupled to the first portion of the transmissionpathway and can output the first inquiry signal. For example, amonitoring device, such as 210 of FIG. 1 can be electrically coupled tothe first portion transmission pathway and output the first inquirysignal. The first inquiry signal will travel along the first portion ofthe transmission pathway and will be received by one or more monitoringdevices located along the first portion of the transmission pathway. Thefirst portion of the transmission pathway is the portion of thetransmission pathway along with the one or more monitoring devices thatreceived the first inquiry signal. The one or more monitoring devicesthat receive the first inquiry signal are a first group of monitoringdevices. The number of monitoring device that receive the first inquirysignal will depend on the characteristics of the first inquiry signaland whether a fault on the transmission pathway blocks the inquirysignal from transmitting further. For example, as the first inquirysignal transmits along the transmission pathway it will experiencelosses, such as decreasing energy. Eventually, these losses will preventadditional monitoring devices further along the transmission pathwayfrom receiving the first inquiry signal. In another example, a faultalong the transmission pathway can block the first inquiry signal fromtransmitting further along the transmission pathway or can causeadditional losses that prevent the first inquiry from transmitting asfar as expected along the transmission pathway.

At 504, first outputs from the first group of monitoring devices arereceived in response to the first inquiry signal. Each of the monitoringdevices that receives the first inquiry signal, which include the firstgroup of monitoring devices, generate and transmit a first output to thebase station. The first outputs will be based on a performance featureof a response signal that each of the group of monitoring devicesreceives. In the process 500, the response signal received by each ofthe first group of monitoring devices is based on the first inquirysignal. Based on the received outputs, the base station can determinewhich monitoring device of the first group of monitoring devices islocated the furthest along the transmission pathway, i.e. the lastmonitoring device that received the first inquiry signal.

At 506, an instruction for one of the first group of monitoring devicesto output a subsequent inquiry signal along a subsequent portion of thetransmission pathway can be generated. For example, the base station cangenerate and transmit an instruction to the last monitoring device thatreceived the first inquiry signal. The instruction can cause the lastmonitoring device to output the subsequent inquiry signal along thetransmission pathway. The subsequent portion of the transmission pathwayis the portion of the transmission pathway immediately after the firstportion. In this manner, the first inquiry signal is used to interrogatethe first portion of the transmission pathway up to the point along thetransmission pathway the first inquiry signal stops being received. Thelast monitoring device to receive the first inquiry signal can thenoutput the subsequent inquiry signal to interrogate further along thetransmission pathway, the subsequent portion of the transmissionpathway. Rather than having each individual monitoring device along thetransmission pathway output their own inquiry signal as described above,the inquiry signal is output as needed along portions of thetransmission pathway. Doing this can reduce the energy expenditure ofthe individual monitoring devices and extend the operating life of themonitoring devices.

The subsequent inquiry signal transmits along the subsequent portion ofthe transmission pathway and is received by additional monitoringdevices, a subsequent group of monitoring devices. The subsequent groupof monitoring devices are the monitoring devices that receive thesubsequent inquiry signal. Like the first inquiry signal, losses due tothe transmission pathway or a fault limit how far along the transmissionpathway the subsequent inquiry signal transmits. In some examples, thesubsequent group of monitoring devices may not include any monitoringdevices if there is a fault on the transmission pathway that preventsthe subsequent inquiry signal from being received by any monitoringdevices.

At 508, subsequent outputs from the subsequent group of monitoringdevices are received in response to the subsequent inquiry signal.Similar to the first outputs, the subsequent outputs are based on aperformance feature of the response signal received by each of themonitoring devices of the subsequent group of monitoring devices. Alsosimilarly, the response signal received by each of the monitoringdevices of the subsequent group is based on the subsequent inquirysignal. As previously mentioned, there may be no subsequent outputs if afault on the subsequent portion of the transmission pathway prevents anymonitoring devices from receiving the subsequent inquiry signal.

At 510, a fault along the first or subsequent portions of thetransmission pathway can be identified based on the first and subsequentoutputs. For example, the base station can analyze or evaluate the firstand subsequent outputs to identify if a fault is present on the firstportion or the subsequent portion of the transmission pathway.Additionally, the base station can evaluate the first and subsequentoutputs to determine a location and type of a fault on the first orsubsequent portions of the transmission pathway. As previouslymentioned, there may be no subsequent outputs if a fault is immediatelyafter the last monitoring device that sent one of the first responses.The base station can use the lack of subsequent responses to identifythe fault and determine that the location of the fault is between thelast monitoring device that sent one of the first responses and asubsequent monitoring device. If a fault is not identified, the process500 can continue back at 506 to analyze further portions of thetransmission pathway. This process can be repeated until the entiretransmission pathway has been evaluated for faults.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the disclosure.However, it will be apparent to one skilled in the art that the specificdetails are not required in order to practice the systems and methodsdescribed herein. The foregoing descriptions of specific embodiments orexamples are presented by way of examples for purposes of illustrationand description. They are not intended to be exhaustive of or to limitthis disclosure to the precise forms described. Many modifications andvariations are possible in view of the above teachings. The embodimentsor examples are shown and described in order to best explain theprinciples of this disclosure and practical applications, to therebyenable others skilled in the art to best utilize this disclosure andvarious embodiments or examples with various modifications as are suitedto the particular use contemplated. It is intended that the scope ofthis disclosure be defined by the following claims and theirequivalents.

The invention claimed is:
 1. A cell tower monitoring and diagnosticsystem having multiple monitoring devices that are each electronicallycoupled to a cell tower transmission pathway at various locations, themultiple monitoring devices including a first portion of monitoringdevices located along a first portion of the transmission pathway and asecond portion of monitoring devices located along a second portion ofthe transmission pathway, the multiple monitoring devices alsoelectronically coupled to a base station that receives output from themultiple monitoring devices, the system comprising: a processorconfigured to: receive a data message from the base station, the datamessage including: a first output from the first portion of monitoringdevices, the first output including a first performance feature of thefirst portion of monitoring devices, an indication of whether, based onthe first output, a second inquiry was sent to the second portion ofmonitoring devices, and based on the first output, an identity of afault on the transmission pathway in one or both of the first portion orthe second portion of monitoring devices; use the message to request todispatch a technician, the request generated in response to theidentification of the fault in one or both of the first portion or thesecond portion of monitoring devices, the request including datarelating to the identification of the fault in either or both of thefirst portion or the second portion, and an output configured to outputthe request.
 2. The system of claim 1, wherein the first performancefeature of the first portion of monitoring devices is a response to afirst inquiry signal sent along a first portion of the transmissionpathway corresponding to the first portion of monitoring devices.
 3. Thesystem of claim 2, wherein the first inquiry signal is a low frequencypulse in the range of 100 Hertz (Hz) to 500 Hz.
 4. The system of claim1, wherein the first portion and the second portion of monitoringdevices are positioned in series along the transmission pathway.
 5. Thesystem of claim 1, wherein the first portion and the second portion ofmonitoring devices are positioned in parallel along the transmissionpathway.
 6. The system of claim 1, wherein the first output includes a4-bit to 8-bit data transmission from one monitoring device of the firstportion of monitoring devices.
 7. The system of claim 1, wherein thefirst performance feature includes one or both of a frequency of thefirst output and an energy of the first output.
 8. The system of claim1, wherein the data message further includes: a second output from thesecond portion of the multiple monitoring devices, the second outputincluding a second performance feature of the second portion ofmonitoring devices, the second output generated in response to a secondinquiry transmitted to the second portion of monitoring devices, thesecond inquiry transmitted in response to the first output.
 9. Thesystem of claim 8, wherein the data message further includes an identityof the fault on the transmission pathway in the first portion ofmonitoring devices.
 10. The system of claim 8, wherein the data messagefurther includes an identity of the fault on the transmission pathway inthe second portion of monitoring devices.
 11. The system of claim 8,wherein the data message further includes an identity of the fault onthe transmission pathway in the first portion and the second portion ofmonitoring devices.
 12. The system of claim 8, wherein the requestincludes data relating to the identification of the fault in the firstportion of monitoring devices.
 13. The system of claim 8, wherein therequest includes data relating to the identification of the fault in thesecond portion of monitoring devices.
 14. The system of claim 8, whereinthe request includes data relating to the identification of the fault inthe first portion and the second portion of monitoring devices.
 15. Thesystem of claim 1, wherein the request to dispatch the technicianincludes one or both of a type or a location of the identified fault,the type or location based on the first performance feature.
 16. Thesystem of claim 1, wherein the first performance feature includes areturn time to receive the first output from the first portion ofmonitoring devices in response to an inquiry signal.
 17. The system ofclaim 1, wherein the first performance feature includes a differencebetween a frequency of an inquiry signal and a frequency of the firstoutput.
 18. The system of claim 1, wherein the first performance featureincludes a difference between an energy of an inquiry signal and anenergy of the first output.
 19. The system of claim 1, wherein the datamessage includes an identification of a transmitting monitoring devicein the first portion of multiple monitoring devices.
 20. The system ofclaim 19, wherein the data message further includes a location of thefault along the transmission pathway that is based on the identifiedtransmitting monitoring device.